1. Field of the Invention
This invention relates generally to particle detection and, more particularly, to detecting the presence of bacterial endospores in a sealed container.
2. Description of the Related Art
Recently, mail service within the United States has been disrupted by the spread of anthrax. Such mail service includes the United States Postal Service as well as private carriers such as Federal Express, United Parcel Service (UPS), DHL and the like. Anthrax is spread through bacterial endospores shipped through the mail or other delivery services and strikes its victim, intended or otherwise, once the mail is opened. This is because after the mail is opened, bacterial endospores are dispersed into the air where they can infect the victim either through inhalation or by contacting skin. In addition to anthrax, a bioterrorist can also spread endospores that cause other diseases such as botulism, tetanus and gas gangrene through the postal service.
Infected mail is very dangerous. To date, people who have opened the mail and some postal workers who have merely sorted unopened mail have become infected by means that are still unknown. Opened mail, however, is the most dangerous in that once the mail is opened, small air currents immediately disperse the endospores. This coupled with privacy issues encountered when handling the mail make it desirable to detect the endospores without having to actually open the mail.
Known tests for detecting bacterial contamination are usually slow and often unreliable. Serological methods use antibodies which often have large cross reactivities that can cause false alarms. Mass spectroscopy has extremely complex spectra that are difficult to analyze and could cause false alarms. DNA testing is extremely slow and expensive.
In order to be an effective bioagent, endospores must be concentrated. Because bacterial endospores are not commonly found in nature, their ambient concentration is extremely low. As a result, the concentration of these endospores in poisoned mail is very high and a large quantity of endospores in a piece of mail is very likely to represent a bioattack involving anthrax, tetanus, gas gangrene or botulism. Therefore, a device and method that allows for the fast and specific detection of endospores without opening the mail or, at the very least, that only creates a small puncture or cut in the mail that can be rapidly sealed so that the bacteria either never leave the mail or are deposited in an aerosol concentrator would be an important improvement in the art.